1. Field of the Invention
The present invention relates to a device housing a battery (or batteries) such as a battery pack or mobile telephone, and to a charging pad that transmits power by magnetic induction to the device housing a battery to charge the battery inside.
2. Description of the Related Art
A charging pad (charging stand, charging cradle) has been developed to charge a battery housed in a device by transmitting power from a transmitting coil (power supply coil, primary coil) to a receiving coil (induction coil, secondary coil) by magnetic induction. (Refer to Japanese Laid-Open Patent Publication H09-63655 (1997).)
JP H09-63655A cites a configuration with a charging pad housing a transmitting coil driven by an alternating current (AC) power source, and a battery pack containing a receiving coil that magnetically couples with the transmitting coil.
The battery pack houses circuitry to rectify AC power induced in the receiving coil and supply the rectified power to charge the battery. With this system, a battery pack can be placed on the charging pad to charge the battery pack battery without direct physical contact.